#include"main.h"
void TIM2_PWM_Init(u16 arr,u16 psc)
{  
	 GPIO_InitTypeDef GPIO_InitStructure;
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	TIM_OCInitTypeDef  TIM_OCInitStructure;

	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);// 使能TIM1时钟
 	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);  //使能GPIO外设时钟使能
	                                                                     	

   //设置该引脚为复用输出功能,输出TIM1 CH1的PWM脉冲波形
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource3,GPIO_AF_TIM2);
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3; //TIM_CH4
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  //复用
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
	GPIO_InitStructure.GPIO_OType=GPIO_OType_PP;
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource2,GPIO_AF_TIM2);
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; //TIM_CH3
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  //复用
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
	GPIO_InitStructure.GPIO_OType=GPIO_OType_PP;
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值	 80K
	TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值  不分频
	TIM_TimeBaseStructure.TIM_ClockDivision =TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位

 
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
	TIM_OCInitStructure.TIM_Pulse = 0; //设置待装入捕获比较寄存器的脉冲值
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高
	TIM_OC4Init(TIM2, &TIM_OCInitStructure);  //根据TIM_OCInitStruct中指定的参数初始化外设TIMx
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
	TIM_OCInitStructure.TIM_Pulse = 0; //设置待装入捕获比较寄存器的脉冲值
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高
	TIM_OC3Init(TIM2, &TIM_OCInitStructure);  //根据TIM_OCInitStruct中指定的参数初始化外设TIMx
	TIM_Cmd(TIM2, ENABLE);  //使能TIM1
	TIM_CtrlPWMOutputs(TIM2,ENABLE);	//MOE 主输出使能	

	TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Enable);  //CH4预装载使能	 
	TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Enable); 
	
	TIM_ARRPreloadConfig(TIM2, ENABLE); //使能TIMx在ARR上的预装载寄存器
	

   
}
